Chapter 3: Developing a Serverless Function with Lambda

1. What's the command-line command to create an IAM role for an AWS Lambda function?

Answer: Create an IAM role with the below command; it allows Lambda function to call AWS services under your account:

aws iam create-role ROLE_NAME --assume-role-policy-document file://assume-role-lambda.json

 

 

 

 

 

 

The assume-role-lambda.json file contains the following:

{
"Version":"2012-10-17",
"Statement":[
{
"Effect":"Allow",
"Principal":{
"AWS":"*"
},
"Action":"sts:AssumeRole"
}
]
}

2. What's the command-line command to create a new S3 bucket in the Virginia region (us-east-1) and upload a Lambda deployment package to it?

Answer: The following command can be used to create an S3 bucket:

aws s3 mb s3://BUCKET_NAME --region us-east-1

To upload the deployment package to the bucket, issue the following command:

aws s3 cp deployment.zip s3://BUCKET_NAME --region us-east-1

3. What are the Lambda package size limits?
   • 10 MB
   • 50 MB
   • 250 MB

Answer: AWS Lambda deployment package has a total maximum of 50MB zipped and 250MB uncompressed.

4. AWS Lambda Console supports editing Go source code.
   • True
   • False

Answer: False; Go is a recently added language, and the developers behind it haven't added the capability for an inline editor yet. Hence, you must provide an executable binary in a ZIP file format or reference an S3 bucket and object key where you have uploaded the deployment package.

 

5. What's the underlying AWS Lambda execution environment?
   • Amazon Linux Image
   • Microsoft Windows Server

Answer: AWS Lambda execution environment is based on Amazon Linux AMI.

6. How are events represented in AWS Lambda?

Answer: Events in AWS Lambda are represented in a JSON format.